Such a mechanism applies particularly well to a chronograph mechanical watch movement displaying the hour and the minute of the measured time with the aid of disks. In this case, the minimum determined period is equal to the maximum measurable time.
It is known that this type of display, better than a display by hands, makes it possible to provide indications of large dimensions, hence quicker and easier to read, as may be desired, for example, by aircraft pilots.
The problem that then arises is that of the mechanical energy necessary to drive the disks. Specifically, the single barrel risks being under stress, which disrupts the amplitude of the oscillations of the balance and, consequently, the correct operation of the chronograph gear-train.
EP application No 03 405532.7 provides a solution to this problem by proposing a movement in which the disks of the hours, the tens of minutes and the units of minutes of measured time are each driven by their own barrel.
In such a product, it is very useful, to perform the chronograph function over a minimum period, for the wearer to have an indication of the running reserve the movement has, both for the basic function and for the chronograph function.
The object of the present invention is to respond to this need.